51 lines
1.1 KiB
Rust
51 lines
1.1 KiB
Rust
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// check-fail
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use std::fmt::{self, Display};
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struct Mutex;
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impl Mutex {
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fn lock(&self) -> MutexGuard {
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MutexGuard(self)
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}
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}
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struct MutexGuard<'a>(&'a Mutex);
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impl<'a> Drop for MutexGuard<'a> {
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fn drop(&mut self) {
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// Empty but this is a necessary part of the repro. Otherwise borrow
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// checker is fine with 'a dangling at the time that MutexGuard goes out
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// of scope.
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}
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}
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struct Out;
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impl Out {
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fn write_fmt(&self, _args: fmt::Arguments) {}
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}
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impl<'a> Display for MutexGuard<'a> {
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fn fmt(&self, _formatter: &mut fmt::Formatter) -> fmt::Result {
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Ok(())
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}
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}
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fn main() {
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// FIXME(dtolnay): We actually want both of these to work. I think it's
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// sadly unimplementable today though.
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let _write = {
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let mutex = Mutex;
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write!(Out, "{}", mutex.lock()) /* no semicolon */
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//~^ ERROR `mutex` does not live long enough
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};
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let _writeln = {
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let mutex = Mutex;
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writeln!(Out, "{}", mutex.lock()) /* no semicolon */
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//~^ ERROR `mutex` does not live long enough
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};
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}
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